Pneumatic action



W. 1. WODRASKA.

PNEUMATIC ACTION.

APPLICATION man )uns 26. 1920.

1,396,492. PatemaNov. 8,1921.

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""5 /lvvENToR W2 mg A Ano/'Mfrs UNITED STATES WALTER J. XVODRASKA, OF NEXV YORK, N. Y.

PNEUMATIC ACTION.

Specification of Letters Patent.

Patented Nov. 8, 1921.

Application iled June 26, 1920. Serial No. 391,856.

To @ZZ whom it may concern.'

Be it known that I, VALTER J. lVoDRAsKA, a citizen of-the United States, and a resident of the city of New York, borough of Manhattan, in the county and State of New York, have invented a new and Improved neumatic Action, ofvwhich the following is a full, clear, and exact description.

This invention relates to pneumatic actions for musical instruments or the like, and has particular reference to attachments of this character for automatic player pianos.

Among the objects of the invention is to improve the details of construction, having reference to the 'valve chests and the valve mechanism therein, the position of the pneumatics with respect to the valve chests so as to conserve space vto the best possibleV advantage, and to improve the operative connections between the pneumatics and the key operating mechanism.

With the foregoing and other objects in view the invention consists in the arrangement and combination of parts hereinafter described and claimed, and while the invention is not restricted to the enact details of construction disclosed or suggested herein, still for the purpose of illustrating a practical embodiment thereof reference is had to the accompanying lrawings, in which like reference characters designate the same parts in the several views, and in which` Figure 1 is a vertical transverse section on approximately the line 1-1 of Fig. 2.

Fig. 2 is a horizontal section on the line 2-2 of Fig. 1.

Fig. 3 is a side elevation of that part of the mechanism that would be visible from the plane indicated by the line 3-3 off Fig. 4 is a detail perspective view of the adjustable stop fitted to the abstract.

Fig. 5 is a partial end elevation of a modied arrangement of the pneumatics.

Fig. 6 is a diagrammatic side elevation indicating the relation of the valve blocks and pouch boards to one another and the main vacuum casing.

eferring now more specifically to the drawings I show a construction involving the use of a. casing l0 having a vacuum space 11 therein, the vacuum being determined and maintained by any approved means with which I am not concerned at this time. The casing 10 includes a top plate 12 into which arrangement or dis- Y space. In the normal y the air chamber the air ducts 13 lead from the not shown, through idividual plate 12 and communicating upper portion flenible tubes 1G ports 111 in the ports 15 in the of the casing proper. The serve to establish communiand superposed valve blocks 17 located within the vacuum space, which vacuum space is divided into three independent valve housing chambers by means of the vertical partitions 17', as illustrated in F ig.y G. In each valve block 17 are arranged vertically movable valve devices each comprising upper and lower valves 18 and 19 fixed to the same stem 2O and adapted to cooperate in alternation with the upper and lower valve seats 21 and 22 respectively. To the lower end of each valve stem is fined a head 23 cooperating with a iiexible diaphragm 24 spanning the vacuum pit 25 formed in a pouch board 17a spaced tracker board,

below each vvalve block 17 and from which a bleed port 26 leads to the main vacuum position the valve 19 is seated downward upon the seat 22 closing the oassageway through the valve seat and preventing communication between the vacuum space and the air chamber 27 of the valve casing. Atmospheric pressure obtains normally within each pneumatic 28:l or 28b reason of the ports 29 and 30 to and from 27. At this time the valve 18 is spaced downward below the valve seat 21 so that the air pressure is the same on both sides of the valve 18. lla/Then, however, the condition of vacuum Ais broken in the pit 25 by the admission of a jet or" air downward through the ports 13, 14, 15 and 16, the diaphragm acting through the head 23 lifts the valve stem and so unseats the valve 19 and closes the port at the valve 18, thus the air pressure within the pneumatic is eX- austed through the valve seat 22 into the vacuum space 11. As soon as the port 13 is closed again at the tracker board equilibrium of pressure will be restored on opposite sides of the diaphragm 24 by means oi' the bleed 26 and the force of suction acting upon the valve 19 will reseat it upon the seat 22. is arrangement of the valve blocks and valves therein is exceedingly simple and they may easily be inspected or repaired if necessary by simply first removing the side plate 31 of the vacuum chest or casin By arranging the pneumatics one in vertical position and the other in horizontal position across the bottom of the casing space is con- Vpivot block 38.

served, a feature of very great structural importance in musical instruments. The pneumatic 2Sa collapses to the right toward the valve casing while the other pneumatic oi' each pair collapses upward. i

A bar 32 constitutes a- Xed portion of thel structure and to this bar are secured pairs of anges 33a and 331 to which are severally pivoted at 34 a bell crank' and an arm 36. Each bell crank is connected to a pneumatic 28a by means of a link 37 and The arm 36 is pivotally connected to each pneumatic 26b through a link 39 and a pivot block 40. rThe forward the abstract-44 and having a lug 45 extend-V end of each lever element 35 or 36 is rounded and faced as shown at 4i with felt or itsy equivalent for cooperation with a stop niember 42 shown in detail in Fig. 4 and comprising a hollow body 43. embracing any suitable'part of the key mechanism such as ing into co'ntact'with said bearing surface 4l. The upper end of the abstract is pivoted at 46 to the wippen 47 which in turn is pivoted at 48 to a flange 49. The lower portion of the abstractie pivoted at 5() to a flange 5l through a link 52. A stop member 53 cooperates with the lower end of the abstract to limit its downward movement.

VThe main portion of the stop 42 is made preferably l metal or'the like, the lug portion 45 being an extension from the body portion and being of sheet material adapts itself readily tothe form of a'spring tongue 45 which has direct contact Vwith the arm or lever mechanism. The body portion is wider than the abstract and in the spacing thus provided is arranged a leaf spring 54 Xed to the side of the body at 55 remote from the lug 45. One end, preferably the upperend, of this spring is provided with a knife edge 54 which has a biting action along one edge or face of the abstract so aS to render it pracfrom a single vpiece of sheet tically impossible for the stop 42 to become misplaced along the abstract, while the lower end of the spring is adapted to glide freely downward during the adjustment of the stop bythe operator to adapt it to the desired part of the abstract. rlhe downward movement of the levers and armsV 35 and 36 is limited by means of a locking bar 56 hinged at`57 to the edge of the bar 32. The weight of the key operating mechanism including the abstract and parts attached thereto insures the prompt return ofthe nneumatics to the normal position indicated in the drawings after each actuationof the valve mechanism. v

l claim 1. ln a pneumatic action for Vplayer pianos, the Vcombination with a 'main' casing and a plurality of pneumatics carried thereby and arranged in pairs,one pneumatic of each pair being arranged verticallyand the other horizontally, of key actuating means including a bell crank for each vertically arranged pneumatic, and an arm for each horizontally arranged pneumatic.

2. A device of the nature set forth in claim 1 in which the bell cranksv and arms are pivoted coaxially of one another.

3. A device as set forth in claim l in which the key actuating ends of the levers Y Y WALTER'J. YWODRriSKA.. 

